If your sysnand is unchanged and only Emunand is updated, eg sysnand 4.1 Emunand 6.2, don't need autorcm, your fuses will never burn.
For your fuses to burn you have to boot into OFW, but Emunand is completely seperate from OFW so that will never happen. Just use jig and dongle, if you boot into OFW by mistake nothing will happen.
Autorcm is only for CFW that lives on sysnand.
I don't think you back up Emunand, there isn't much point. If there is a problem you just wipe it and make a new one.